-LRB- CNN -RRB- -- A mother and two children drowned inside a car Friday after floodwater washed their vehicle away , a Pittsburgh city official said .

The city experienced a heavy storm and flooding shortly after 4 p.m. Friday , said Michael Huss , Pittsburgh director of Public Safety .

`` The manhole covers began to lift from the rush of water , and the roadway flooded , '' Huss said .

CNN affiliate WTAE reported that the incident took place in the eastern Pittsburgh neighborhood of Highland Park in Pennsylvania .

Huss said the family 's vehicle washed down the roadway and got stuck next to a tree .

`` The three could not get out of the car before it was submerged , '' Huss said . `` The water had a lot of force behind -LRB- it -RRB- , and all three inside drowned . ''

In addition , Huss said , `` We have one person whose car was located , but that person is still unaccounted for . ''

Dive units were searching late Friday night .

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Floodwater washes a family 's vehicle away in Pittsburgh

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The car gets stuck next to a tree and is submerged

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One more person whose car is found remains unaccounted for